How to add an icon for submenu in Quick Controls 2?

I'm creating a Windows desktop application with Qt Creator 4.8.0 & Qt 5.12. I have no problem adding an icon for a MenuItem since it has an icon.source property. But how should I achieve the same effect for a submenu?

A Menu component becomes a submenu when it is defined inside the scope of the upper-level Menu component. And at this time it looks like a MenuItem with an arrow on the right side.

Yes, I understand your code. But I think you are using Qt Quick Controls 1, which has an iconSource property for Menu component. But in my case, I'm using Quick Controls 2 and for the Menu type, only the title can be specified.